Heat & Electricity with Lighting in Photographing Paintings

<p>Hello,
<br>

<br />I've been reading through this forum and have a much better idea of how to approach this, but my situation leaves me with some questions. I'm trying to get high resolution images of my paintings. The paintings are usually 3' x 4' or 4' x 4'. I would like to have the option of printing them real size. I have a Canon 5d so it will require me to shoot the paintings in something like 9 to 16 sections, rather than straight on. My frame should cover about 20" x 13" for each section, so I don't think lighting the entire painting is necessary. Trying to light the entire painting might have me creating shadows, as I will have to be closer in shooting it will a 50mm lens. This is part of the question - is this an incompatible light kit for lighting paintings in a small/medium room? I was looking into (4) 1000 watt tungsten focusing lights. https://www.bhphotovideo.com/c/product/285849-REG/Lowel_D2_94Z_DP_4_Four_Light_Kit.html I was planning to try it with 500 watt bulbs at first. But if I am going to spend a lot of money on lights I would prefer to have the option to use them for video work as well. That's why I'm not so interested in strobes or lights with a much lower wattage. I also read here that strobes give off a high level of UV, which is a concern to paintings.</p>

<p>I know the tungstens will pose an issue with heat and the number of amps required to power them. Someone mentioned using "a variac or series parallel switch" to regulate heat, while adjusting the lights and only using full power for the actual seconds shooting. I had to look up what a variac was and I couldn't find what a "series parallel switch" was. Looking at variacs, the largest amount of amps one would accept is 30 amps https://www.circuitspecialists.com/variac-tdgc-3kva.html How can it be so difficult to find one that accepts the amount of amps required to power a medium size light kit? If I use (4) 500 watt bulbs instead of the 1000 watt ones does that mean I can reduce the amount of amps needed to roughly 20 amps instead of 40 amps?</p>

<p>I'm also concerned with the amount of amps needed from the outlets. How do you actually determine what outlet is a separate circuit from another? It seems a little crazy that I should need to find 3 more separate circuits, besides my room's, (if they have 15 amps each) to power a light kit. Am I missing a convenient technical answer to this? It doesn't look like I would be much better off with strobes in that regard either. Looking at the White Lightning series it says all the models require 6 amps each. So that's a bit better than the 1000 watts but also worse than 500 watt tungstens.</p>

<p>I know I'm being a bit complicated trying to combine cinematography with photography in one light kit. Anyway, I appreciate any help!</p>

<p>Unless your room is very small, 2 broad lights (I used to use Lowel TotaLights for this quite successfully) should do it for this size painting. 2 of these with 500 watt bulbs will work on a 10 amp circuit, with 750's on a 15 amp circuit. Any legal wiring from the last 40+ years should be able to handle this, if you're not also running other things on that circuit. Be aware that voltage changes will affect the color of the light, so if you forget to set the rheostat to full power, things will go orange. I switched to White Lighting studio strobes a long time ago to get consistent, constant color temperature, faster shutter speeds and lower heat output, but I am only interested in still photography. But I would point out that the White Lighting x series use a 250 watt quartz bulb. If 250 watts is enough light for your video needs, these lights might do both jobs for you.<br>

As for checking circuits, plug lamps into all of the receptacles and then go to the circuit breakers and turn them off one at a time and see what shuts off. You can then map out what plugs are on which circuits. Labels on the receptacles are a good idea.<br>

As for the camera/lens, you might want to consider a longer focal length macro lens like a 100-105. That would help a lot with eliminating potential shadows. A solid tripod will also be essential for this work.</p>

<p>Are you shooting in a residence or commercial studio? I assume the former? Electrical circuits in most houses are rated 15 amps per circuit non-continuous. A single circuit/breaker will usually feed numerous outlets and lights so in addition to your studio lights there are other lights and appliances drawing some of those amps on each circuit.</p>

<p>The non-continuous part is critical as a continuous load down rates the circuit to 80% or IOW 12 amps for a 15 amp (14 gauge wire) circuit. Also, depending on the wire used and length of the run you'll find that pushing the upper bounds can wreak havoc with the voltage leading to color problems. </p>

<p>A typical household 15a circuit can handle a single 1000w lamp or 2 500w lamps. NO MORE. So any other lights or appliances on this circuit need to be unplugged if possible to avoid phantom drain and RF problems or at least turned off. If you want to go this route I would suggest hiring an electrician to install the appropriate dedicated circuits (noting that they are likely rated as continuous loads). Also ask them to let you know if your service entrance will be able to handle the additional load without voltage drops.</p>

<p>Four 500w incandescent lamps in a small room will heat it up very quickly. How do you plan to deal with the heat?</p>

<p> </p>

<p>Thank you both for your assistance. I'm shooting in a residential home. This is all beyond me - I've only just now started to realize how much more familiar I need to be with the electricity. I've never touched a circuit breaker. I might have to hire an electrician like you said. That's a good idea to turn off the circuit breakers one by one to chart everything out.</p>

<p>The heat is another big concern. I was hoping that using a dimmer/variac, to keep the lights low while situating them, would be adequate, in only turning the lights all the way up for the seconds spent shooting. I'm starting to consider those White Lightning strobes a lot more now.</p>

<p>I guess just 2 of those strobes might be all I would need, especially since I'm shooting in small sections. Would you recommend using white umbrellas or softboxes for this? I always see it done with umbrellas but I have also read that using lights straight on without diffusion is the way to go. I was planning to stick with the 50mm lens because I think it might be my sharpest lens. But a longer focal length macro lens might be something I should look into. I've got old Nikon lenses that are longer focal lengths, but they require an adapter for my Canon and I'm suspicious that may start to render a less sharp image. I should compare both approaches.</p>

<p>Hard light sufficiently off to the sides will usually give the best results, showing the texture of the paint most effectively while limiting glare. The standard 80 degree reflectors for the White Lightning X series are what I use for this and they work well, putting out an even light without hot spots. When you set up to light your paintings, light them evenly (best done with the aid of an incident light meter) and don't move the lights. You should also be aware that a standard telephoto or zoom lens may have some distortion at the edges which can make combining images difficult. Macro lenses generally have much less barrel/pincushion distortion than zooms. The alignment with the original painting will be critical for this to work if you expect to make large prints. If I were you and expected to do a lot of this I would upgrade the camera and lens so that I could do this in one or two exposures, not 9-16 sections. If it is only a few paintings, it might make a lot more sense to hire a pro who is experienced and equipped to do the job. </p>

<p>Alignment is the biggest headache about this. I've been trying to think of a way to get even, parallel shots but I think I will have to gauge as best I can. I was kind of hoping that Lightroom and Photoshop would help with any lens distortion or slightly inconsistent angles. I was curious to see if large format digital cameras might exist, but from what I found only medium format ones are made digital. Even if I had the insane cash for the PhaseOne XF100mp I would still need 10 more inches worth of pixels to cover the whole painting. The Canon 5ds could do it in maybe 4 sections.</p>

<p>I will have more paintings than this current few to need the same resolution photos of. I have thought of taking them to a place that does this with scans. However I would need to rent a truck of some sort to transport them and it all starts to add up to the same price of owning a lot of this photography equipment.</p>

<p>I've actually been considering getting more experienced with this kind of work to offer it beyond my own needs in freelance. That's another reason I'm determined to see what I can do and hopefully build up more experience in this area.</p>

<p>Most dimmers (triac based) and variacs will generate heat themselves so be cautious with that.</p>

<p>A strobe like a white lightning keeps the light source isolated from the electrical service so in addition to not needing as much power to begin with you don't need to worry as much about voltage drop. </p>

<p>What have museums and galleries told you about how they go about this?</p>

<p>Most recently refurb kitchens/dining rooms will have 20A circuits (more watts)....will let you put some lights on it comfortably. When I was involved with film, the HMI units were preferred, since the color balance would not go down with the age of the bulb....just saying. I'm sure you could rent these too.</p>

<p>Les</p>

The amount of UV exposure from using flash

should be of absolutely no concern. The flash

duration is a few milliseconds at most, and in any

case most speedlights and quality strobes have a

UV absorbing coating on the tube.

 

 

I don't think it wise to try and light and shoot the paintings in small sections. This will give you issues with consistency of lighting, together with correcting any lens vignetting and distortion. The direction of lighting will also change from section to section, and this will be a big problem if the paintings have any deep texture. Frontal lighting would minimise this, but then you'd have to deal with specular reflection from the surface of the paintings.

 

 

So the answer is to light the paintings in their entirety, and only to shoot them in sections if absolutely necessary. And since most paintings don't contain fine enough detail to trouble the resolution capability of a modern DSLR, then a 3 by 4 foot print shouldn't be too demanding.

 

PS. If you're having the paintings professionally reproduced, then why not let the printing house scan them? Or invest in an A3 scanner and scan them yourself in sections. Easier than setting up a copy studio for yourself.

<p>I'm not in contact with any museums or galleries, but that's definitely something to consider looking into. It hadn't occurred to me to research anything other than what other artists are doing to try to sell prints, but I guess they must usually limit themselves to prints within 18" x 12".</p>

<p>That's good to know about the HMI's. I haven't looked into them because of the prices, but yeah something to see about renting some time. </p>

<p>There’s another forum thread where it is mentioned that strobes are so taboo with some galleries due to UV damage, that some customers will reject the photographer altogether. They also go on to say that is only some who take this position though. But you might be right, it may be an unnecessary concern. I do see that some UV gels can be applied, so I would think it’s fine.<br /><br />Yeah, I realized I was thinking with a video mindset in thinking I could relight every new section. A longer focal length lens is probably the only option. <br /><br />I don’t think detail in a painting is ever a consideration of intricately fine or not. It’s preferable to look at paintings up close and anything printed less than 300 dpi is going to look awful.<br /><br />I like the idea of looking into scanners though. I looked passed that thinking the kind I would need would be terribly expensive. I should see about that option though. But in having a place do the prints for me I would just send them a digital file to print from, so that's why it would be a big ordeal to look to them for taking care of the scanning.</p>

<p>As for the UV, most modern studio strobes will have UV coated tubes that will stop the UV at the source. They do this to prevent UV light from affecting the color rendition, particularly of color slide film. Some Ektachrome films and Fuji Astia in my experience were particularly sensitive to UV and the colors would go blue or purple without UV filtration on the lights. Some prints on papers made with optical brighteners would also not photograph well unless UV was filtered out at the source. Since these are your own paintings, I wouldn't worry about the small amount of exposure they would get from using flash in this way. I have photographed work in museums and galleries many times, and no one has ever objected to my using my studio flash units.</p>

There's a big difference between printing at 300

DPI (Dots Per Inch) and having a digital image with

300 PPI (Pixels Per Inch) - not the same thing at all.

It takes at least 4 CMYK printing dots to give any

semblance of a single RGB pixel. So you can pretty

much divide your supposed pixel requirement by at

least a factor of 4.

<p>Those Lowel lights have quite primitive reflectors; they are unlikely to give an even spread. In fact you don't need that much power, I assume you have a tripod, so you could get away with something like the Dedo DLH-4 lights. I suggest you rent a kit first; they aren't cheap but very efficient and have superb otics. Copy lighting is the way to go.</p>